Animated gifs are supported by Outlook both on Windows and Mac.
The reason why the animation doesn't show in your Outlook on Windows can be because of the old version of your Outlook.
The version, which supports animated gifs is 16.0.12325.20344:
The reason why the animation doesn't show in your Outlook on Windows can be because of the old version of your Outlook.
The version, which supports animated gifs is 16.0.12325.20344: